The Washington D.C. Temple also has a star panel and a panel with the big dipper and north star on its doors. I'd like to focus on the three doors pictured above.
The Portland Oregon Temple is breathtakingly beautiful. It has a lot of symbolism (borrowed from the Salt Lake Temple) and adds the symbolic star doors. So what do they mean? Well to figure this out we should first notice that these stars are the same style as those on the eastern three spires (no stars are on the western three spires). This means the stars are high on the temple. On the Salt Lake Temple, the star stones can represent heaven. High on the eastern three spires of the Salt Lake Temple there are forty 5 pointed stars which "may refer also to God's gift of priesthood to guide us, in that they may represent the great and noble spirits in premortality whom God assigned to be rulers in his kingdom." according to the book Sacred Walls by Gerald E. Hansen Jr. Because the Portland Oregon Temple door stars match those on the three eastern spires I would interpret them to mean that the temple is heavenly, the path to heaven, and a place of priesthood. They also sort of remind me of depictions of The Star of Bethlehem so they could also signify that the temple leads us to Christ.
The star doors on the Manhattan New York Temple and the Bern Switzerland Temple look a little different but probably have a similar meaning of representing heaven and heavenly guidance. The stars are eight pointed however so they may have an additional meaning.
Well there you have a little discussion about LDS Temple star doors. Please comment.